Environmental Winemaking 101: UC Davis Demonstrates Model for Sustainable, World-Class Wine
Ten large, shiny tanks stand near the Robert Mondavi Institute for Wine and Food Science at UC Davis, holding more than a year of rainwater and the key to processing food and drink during a drought. The water tanks, and the teaching-and-research winery they support, are showing students and winemakers throughout the world how to reduce processing costs, improve wine quality and protect the planet’s dwindling natural resources.
“It’s about self-sufficiency,” says Roger Boulton, UC Davis professor of enology and chemical engineering. “We’re demonstrating how you can operate a winery, brewery or any food-processing plant with the water that falls and the sun that shines on your roof.”
The work is the latest in more than a century of trail-blazing viticulture and enology science at UC Davis. Industry leaders travel from around the globe to tour the new facility, and Boulton, who spearheaded much of the innovation, is proud to show it off.
The wine industry benefits from sound science, and research benefits from wine-industry support. It’s a two-way street. The late Robert Mondavi said, “90% of what I know about wine I got from UC Davis” before donating $25 million to UC Davis to help build the Robert Mondavi Institute for Wine and Food Science, home to the Department of Viticulture and Enology and its teaching-and-research winery.
Inside this winery is the world’s first wireless fermentation system which transmits all information to a centralized database. It was designed, built, and donated by T. J. Rodgers, a Silicon Valley semiconductor executive who credits UC Davis for helping turn his passion for red Burgundy into his Clos de la Tech winery in the Santa Cruz mountains.
“I had zero knowledge of winemaking when I decided to plant our first Pinot Noir vineyard,” Rodgers said. “Professor Boulton took my calls and UC Davis graduates like John Kelly taught me how to make wine.” Rodgers’ $3.5 million wireless fermentation system allows UC Davis to perform reproducible fermentations with precise temperature control and uniform mixing, critically important for consistently producing quality wines.
The teaching-and-research winery was built to be carbon neutral and operate independently from an outside source of water and energy. It was the nation’s first winery to receive LEED (Leadership in Energy and Environmental Design) Platinum certification, the highest rating for environmental design and construction awarded by the U.S. Green Building Council.
That ranking and Boulton’s vision of a self-sustainable winery so impressed the late Jess Jackson and his wife, Barbara Banke, of Jackson Family Wines, that they contributed $3 million to build the Jess S. Jackson Sustainable Winery Building next door to the teaching-and-research facility.
The Jess S. Jackson building will soon house the water and energy systems to power the winery, which leads us back to the large, shiny water tanks where Boulton awaits. The 40,000-gallon tanks store captured, recycled water and they’re part of the Jess S. Jackson building’s architectural design.
It’s 90° and rising on this bright afternoon as Boulton opens the door to the Jess S. Jackson building. Inside, it’s a pleasant 72°. “That’s not air conditioning,” Boulton says. “To reduce energy use, the building has no air-conditioning or heating, yet it stays about 60° to 72° inside, day and night, all year long.”
The roof extends 25 feet on the east and west sides of the building made of structural insulated panels, forming deep porches to shield it from the sun. The extended roof also provides more room for solar panels and more surface for catching rain. The ceiling and walls are ultra-insulated. Windows near the peak of the slanted ceiling open automatically on hot evenings to release warm air.
“It’s called vertical displacement,” Boulton says. “We wait until the night air is coldest and deliver it to the floor of each room, and that pushes the warm air up and out the windows.”
The building is plumbed to capture carbon dioxide, a natural by-product of fermentation, and convert it into calcium carbonate, otherwise known as chalk. “That way, you don’t contribute to global warming by releasing carbon dioxide into the atmosphere, and you end up with a valuable product,” Boulton explains.
Each day’s solar energy will be directed in a couple ways: to be stored in second life lithium ion batteries, recycled from hybrid and electric vehicles, and to a system that will break down water into oxygen and hydrogen. The hydrogen can operate a fuel cell to provide electricity at night or, if necessary, supplement solar energy during a daytime peak. “The building is designed so that each of these systems can be removed and replaced with a newer model, making it an evolving test-bed and demonstration site for building and process technologies,” Boulton says.
Water is critical to winemakers in drought-stricken California and beyond. Grapes aren’t a very thirsty crop to grow—in fact, UC Davis research has shown that deficit irrigation actually improves the flavor of grapes and wine. But keeping fermenters clean is another story. A typical winery uses four to six gallons of water after the grapes are harvested to produce one gallon of wine, and most of that water is used to wash equipment. Boulton and David Block, chairman of the Department of Viticulture and Enology, are developing self-cleaning fermenters capable of recycling 90% of that water. The goal: affordable technology and alternative practices that use less than one gallon of water to produce one gallon of wine.
Winemakers currently remove sticky, fermented grape residue from tanks with water and elbow grease. Clean-in-place technology replaces hand-cleaning with an automated system that sprays tanks with diluted solutions of potassium hydroxide and potassium bisulfate. “The dairy industry has used clean-in-place technology since the 1960s and the pharmaceutical industry since the 1990s,” says Block, a chemical engineer and enologist who helped the pharmaceutical industry manage clean-in-place technology before coming to UC Davis in 2008. “It’s a little different with dairy and pharmaceuticals, where poor sanitation can kill you, but the concept is similar.”
So the water tanks outside the Jess S. Jackson building have two functions: 1) to store water captured during the wet season to use during the dry season when it’s needed most, and 2) to store filtered and purified water as it’s used and reused to clean fermenters. “We will filter and reuse that water at least five times, hopefully one day up to 10 times,” Boulton says. “It’s not waste water. It has no phosphates, no nitrates and no chlorine. Clean-in-place technology represents a huge potential for water and labor savings.”
Industry is starting to notice. “Clean-in-place technology is very attractive to us,” says Ashley Heisey, director of winemaking at Long Meadow Ranch in Rutherford, California, and a UC Davis viticulture and enology graduate. “Water is such a critical issue. Long Meadow Ranch owners Ted, Chris and Laddie Hall built our facilities with great concern for the environment, and thanks to UC Davis, we can take it one step further.”
In Sacramento, grocer Darrell Corti from Corti Brothers Market says where UC Davis leads, winemakers will eventually follow. “What we know about grape-growing and winemaking is primarily due to the work they do at UC Davis,” Corti says.
And that’s what they’re doing behind those large, shiny tanks next to the freeway at UC Davis: Researchers are working to help winemakers and grape growers sustainably produce premium wine.